gas resistant (proof?) adhesive

I am asking a question with this suggestion. I do not know enough about the heat shrink tube to say it could work. But have had a thought of cutting a ring of the correct tube and use it like the ring you had to cut off on the stock setup. Once in the correct location heat it and it may seal it to the slide? 

That's a thought. I've never used it but they do make Viton heat shrink. I wonder if it might work better as an underlayment though, along the lines of the JB weld idea but doesn't need a lathe (that I don't have anyway).

If you try the heat shrink go with the Marine type, it has a glue/sealant in the inside. That may be a good idea.

I'm reading on several other bike forms, e.g. www.kawasakiforums.com/forum/klx-250s-71...ragm-expanded-40085/   and forum.concours.org/index.php?threads/car...cuum-diaphragm.4393/

That hot water shrinks diaphragms. Usually in the context of ones that were exposed to carb cleaner, which enlarges them, which mine have not. 

But does hot water work in other cases too, where it was made too big? And is the shrinkage permanent? I'm a bit wary of overshrinking it so the top end doesn't fit properly under the cap.  I might have my old pair I can test with but it would be nicer to know without potentially destructive tests...

Hot water won't shrink the diaphragm.  In use, on a hot day, the carbs, and diaphragms will get quite toasty, near boiling water temp.  If the diaphragms shrink when hot, they wouldn't fit the carbs after the first hot ride.

Nessism wrote:

Hot water won't shrink the diaphragm.  In use, on a hot day, the carbs, and diaphragms will get quite toasty, near boiling water temp.  If the diaphragms shrink when hot, they wouldn't fit the carbs after the first hot ride.
 

I agree. Sounds fishy.

I always fix leaking fuel tees with heat shink tubes, they never leaked again......

At the last minute I decided to go with Seal All, because I had some on hand, but then I had a thought. I googled the operating temperature range and it only goes up to 150 degrees F.  Thought that might be pushing my luck, but I don't know how hot that part of the carb gets. I ended up using non-marine heat shrink (no marine available locally in the right size) to widen the groove where the diaphragm rides. It should be good to 200-250 F. One layer was sufficient to make the diaphragm nice and snug, so this should fix any diaphragm related problems. 

Hoping for nice weather someday so I can test it. After my last ride last fall it wouldn't start however, so hopefully I can solve that before nice weather arrives. Anyway I think the heat shrink solution should be a winner. It will sure as heck be a massive improvement over the sloppy loose way they fit previously.

Success! Or at least partial success...the sun came out, I managed to start it, warmed it up, and I took it for a short cold ride. Acceleration seemed good and I was able to get it above 50mph pretty easily, which was the main problem I attributed to leaky diaphragms that I was hoping to fix. But (why is there always a but?) it is running lean and I had to keep it partway choked. So I guess its now back to my 157th carb tinkering session. I think I will just go back and do everything the manual prescribes from scratch, as if I had just cleaned the carbs (but without cleaning them. I think 157 is enough).